Process of manufacturing rocker arm



July 13, 1 A. v. BROGREN 3,194,200

- PROCESS OF MANUFACTURING ROCKER ARM Filed Oct. 19, 1962 2 Sheets-Sheet 1 July 13, 1965 A. v. BROGREN 3,194,200

PROCESS OF MANUFACTURING ROCKER ARM Filed 001.. 19, 1962 INVENTOR.

4X54 K 8ROGRIY BY United States Patent C) PR OQESS @F MANUFA-QZEURENG ARM Axel V. Erogren, Southfreld, Mich, assignor to Parsons Corporation, Detroit, Mich, a corporation of Michigan Filed (let. 1?, 1962, Ser. No. 231,791 3 Qlahns. (fil. lidile) This invention relates to an improved rocker arm and particularly to an improved process of manufacturing the same.

In my Patent No. 2,917,033, dated December 15, 1959, there was disclosed a rocker arm a process or" manufacturing the same which is generan similar to the rocker arm herein disclosed but which differs therefrom in certain important features as will hereinafter appear.

In the rocker arm of the patent, the arm is formd of sheet metal which is fabricated into a generally channel shape and the shaft apertures through the side walls of the channel shape which constitute the bearin gs for mounting the arm upon the rocker arm shaft are somewhat elongate or egg shaped and the lower margins of such apertures'slope outwardly and downwardly away from the interior or" channel shape the roclrer arm its-elf is so mounted upon the rocker arm supporting shaft as to be tensioned upwardly thereagainst so that there are no burrs or rough spots adapted to engage the shaft upon which the arm rocks. Due to the fact that the arm was held tensioned upwardly at all times there was no rattle or noise produced by its rocking movement.

In the instant structure of this application the rocker arm is of generally the same shape, but the apertures through the side walls which encircle the shaft are truly circular and of such a size that the rocker arm is rockably hung upon the shaft and is not tensioned upwardly thereagainst, yet due to the fit of the arm bearings upon the shaft and theirfinish, there is no rattle resulting from the rocking operation of the arm and the bearings smoothly engage the shaft upon which the rocker arm is mounted.

The shaft apertures through the side walls of the instant channel shaped rocker arm register with opposite ends of a substantially semi-circular trough shaped portion formed in the bottom of the channel shape and these shaft apertures are circular. The edges of the side walls which form the boundary of the apertures are smooth and parallel to the axes of the apertures. As a result there is no appreciable leakage of lubricant through the shaftreceiving apertures of the side walls and about the shaft itself and lubricant is held within the channel shape so as to effectively serve its lubrication purpose.

in order to accomplish the accurate and desired piercing of the circular shaft openings through the two side walls of the channel shape, which constitutes the rocker arm, piercing punches are used which are projected through the side walls from the outside inwardly.

in order to support such side walls against deformation under punching pressure of the piercing punches the process includes the step of positioning a supporting die between the side walls of the channel shape, and this supporting die is so fashioned at its bottom end as to exhibit a die face which is complementary to and superposes the semi-circular contour of the trough formed in the bottom of the channel shaped rocker arm. Due to the fact that the supporting die is fashioned as described, it serves to take the thrust inwardly of the punches throughout substantially the entire portion of the side walls of the channel shape through which the apertures are punched, with the exception of that portion of each side wall which constitutes a continuation of the bottom wall trough.

In other words in the punching of the apertures through the two side walls of the channel shape the thrust against the side walls, except those portions thereof which constitute continuations of the trough itself, is done by the supporting die. The thrust against those portions of the side walls which constitute continuations of the trough is done by the bottom of the trough itself. As a result the side walls are pierced or punched with the proper apertures without any resulting deformation.

Other objects, advantages, and meritorious features will more fully appear from the following specification, claims and accompanying drawings:

FIG. 1 is a vertical sectional view through piercing punch mechanism suitable for use in carrying out the process showing the mechanism in position with the piercing punches withdrawn from active operation;

MG. 2 shows punching mechanism of the character disclosed in PEG. 1 showingthe tioning and following piercing of the work;

FIG. 3 is a vertical cross sectional view taken through the piercing punch 20, the bottom of blank l8, and showing in cross section a portion of the die 32 and the workhol er to;

FIG. 4 is a vertical cross of PEG. 3 except that arm is illustrated;

FIG. 5 illustrates schematically the reaming or finish ing of the shaft apertures through the side walls or" the rocker arm with mechanism which is available in the industry; and

FIG. 6 is a plan of a rocker arm being the product; of this invention.

In the patent supra, the rocker arm illustrated was formed of sheet metal as is the rocker arm of this application, but the side Walls of the rocker arm of the patent were pierced from the inside out and the shaft openings were slightly elongate and the bottom margins of the apertures were beveled outwardly and downwardly. The rocker arm of this application differs therefrom in that while the rocker arm itself is of the same general channel shape, the shaft openings are circular and of a size to accurately fit about the shaft upon which the arm is mounted and the edges of the shaft openings are parallel to the axes of such openings, and these edges are finished and smooth.

in carrying out the process of this invention there is provided a generally conventional type of punch mechanism which is somewhat similar to the punch mechanism shown in the patent supra. There is a base member it) through which dcpressible upright supporting rods 12 extend. These rods 12 support a bed plate 14 as shown. Mounted upon the bed plate is a work holding element 16 within which the work in the form of a channel shaped sheet metal rocker arm blank 18 is supported. The opposite side walls of this channel shaped work holder 16 are pierced to receive therethr-ough two opposed reciprocable piercing punches 2% which are circular in cross section. These piercing punches 249 are carried by two opposed horizontally slidable blocks 22 which are supported upon the bed plate 14 to slide therefrom as shown in FIG. 2. These blocks are mounted in guideways 23' which are supported upon the bed plate 14 to travel reciprocably therewith. The piercing punches are mounted upon holdera 21 carried by the blocks 22, and supported for guided travel through bearings formed in the side wall 16 of the work holder as shown in FIGS. 1 and 2.

sectional view similar to that a slightly modified form of rocker piercing punches func The stationary base lid of the mechanism carries cam faced blocks 24 which are shown in FIGS. 1 and 2. The slidable blocks 22 have beveled faces which slide over corresponding beveled faces of the stationary cam faced block 24 when the punching operation is carried out. The bed plate 14 supported upon the pins 12 carries with it the workholder 16, the slidable cam blocks 2.2, the guideways 23, and the piercing punches 26) as illustrated in FIGS. 1 and 2.

The base plate it carries fixed upright guide pins 26 upon which a vertical reciprocable force or upper plate 23 of the punch mechanism is mounted for vertical reciprocation. This plate 28 is provided with pressure blocks 3t) which act upon the guideway members 23 to urge the bed plate downwardly. As the bed plate moves downwardly the blocks 22 .are cammed toward each other and the piercing punches 2d punch apertures through the side walls of the rocker arm channel blank The pressure plate carries a supporting die 32 hereinafter more particularly described but which is a die adapted to be received within the channel shaped iece of work or rocker arm blank 18 as shown in FIG. 2 to support the side walls of such blank for the punching operation.

Each one of the slidable blocks 22 is provided with a shank rod and springs 36 encircle such rods and are held under tension between the nut on the rod and a part at secured to the guideways 23 and movable therewith, whereby the base and the slidable blocks 22 are withdrawn when the pressure plate member 28 is lifted to the position shown in FIG. 1. Generally speaking, this is conventional and no claim is made to such machine structure.

The supporting die $2 is shown more particularly as to the contour of its die face in FIGS. 3 and 4. FTGS. 3 and 4 differ from each other only in that the rocker arm blank identified as 1'3 is of slightly different formation of FIG, 4 from what is shown in FIG. 3 and this has nothing to do with the instant invention. This difference in formation is that in FIG. 4 there is an internal threaded extension 1-9 which is adapted to receive a threaded actuating push rod. It will be noted that the rocker arm shape in FIG. 3 i provided with an oil escape aperture 21 through an upwardly ext-ending portion 23 of the bottom wall of the channel shape which portion 23 forms a seat to receive the end of a push rod.

The blank 1% itself in both figures is channel shaped and has two upright side walls which are disposed in opposition to each other and which are complementary and extend upwardly from the channel shape and are shown as extending all the way around, that is across the ends as well as across the sides of the channel shape. The bottom of the channel shaped blank in both FIGS. 3 and 4 is deformed downwardly into what is described as a trough portion 11% as illustrated in FIGS. 3 and 4. This trough portion is generally semicircular in cross section. its circularity is such as to receive and seat upon a rocker arm supporting shaft which would occupy the position shown by one of the circular piercing punches 29 in FIGS. 3 and 4.

The supporting die 32 which is shown in FIGS. 1 and 2 as carried by the force or pressure plate portion of the press has a bottom end face 32 which is semi-circular in cross section and when the supporting die is projected between the side walls of the trough shaped blank 18, as shown in FIG. 2, superposes the semi-circular contour of the trough portion 19 of the channel shaped rocker arm 18 all as shown in FIGS. 3 and 4. This supporting die element 32 when projected into and between the side walls of the rocker arm blank 18 has its semi-circular die face so positioned that it is complementary in contour to the semi-circular cross sectional shape of the trough 19 as shown in FIGS. 3 and 4. It forms substantially a continuation of the circularity of such trough. The sides of the die which are adapted to be engaged by the side walls of the channel shaped rocker arm blank support such side walls to take the thrust of the piercing punches It will be seen that the opposed faces of this supporting die 32 would, because of the semi-circular shape of its die face 42, support such side walls of the rocker arm blank around the upper part of the aperture formed by the piercing punches 2d. The lower or bottom of the trough portion 19 supports the side walls of the blank where the same form a continuation of such trough. Therefore the side walls of the blank are supported in part by the die 32 and in part by the bottom wall of the trough and the two combined form substantially a complete support so as to prevent undesirable deformation.

It will be observed that the cutting faces of the circular piercing punches Zil are each formed on a bevel .so that the side walls of the channel shaped rocker arrn blank are first engaged and pierced throughout the area of the side walls which is supported by the die 32 and thereafter pierced through the lower portion of the side walls which constitute a continuation of the bottom of the trough shaped deformation of the rocker arm blank.

In the piercing of the side walls of the blank as hereinabove described certain rough edges may be formed and to provide a smooth accurate aperture a conventional reaming tool such as shown in FIG. 5 may be employed. in this figure the blank itself is indicated as 18 as heretofore stated. It may be supported in any suitable manher. The working end of the tool is indicated as 5%) and the rollers are adapted to be expanded by the tapered carrier 52. Such tool is shown as supported by a bearing 52 and carried by an operating head or chuck 54% to be projected and withdrawn in a manner well understood and to which no claim is here made. Any suitable equivalent finishing operation might be employed.

What I claim is:

1. That process of forming a rocker arm comprising shaping a piece of sheet metal into a channel shape having opposed side walls extending upwardly from the bottom of the channel shape and so shaping the same as to deform the bottom of the channel downwardly into a trough extending transversely of the channel and spaced between the opposite ends thereof and so shaping said trough that it constitutes in cross section substantially a semi-circle, positioning a supporting die having an upwardly concave substantially semi-circular in cross section bottom end die face which is complementary with the semi-circular cross sectional shape of said trough between the side walls of the channel shape superposing said trough and supporting said side walls against piercing pressure from the outside inwardly, and so positioning said die that the semi-circular bottom end face thereof forms substantially a circular continuation of the inner semi-circular contour of the trough, advancing a piercing punch which is circular in cross section through each side wall of the channel shape from the outside inwardly and at opposite ends of the trough forming a circular aperture in each side wall of the channel shape and wherein said two apertures are disposed in axial alignment and with the bottom substantially semi-circular portion of each aperture registering with the arcuate planar continuation of the major portion of the semicircular contour of the side wall bottom of the trough and with the upper semi-circular portion of each aperture registering with the cross sectional shape of the bottom end face of the supporting die that is positioned between the side walls.

2. That process of forming a rocker arm as defined in claim 1 characterized in that the piercing punch face is so formed that the side walls of the channel shape are first pierced by the punches adjacent to the supporting die and thereafter pierced adjacent to the bottom wall of the trough.

3. That process of forming a rocker arm as defined in claim 1 characterized in that following the piercing of 5 the circular apertures through the side Walls of the channel shape said apertures are subjected to a finishing uperation.

References Cited by the Examiner UNITED STATES PATENTS 1,196,667 8/16 Dallrneyer 113-116 1,834,638 12/31 Pedepsen 113116 6 2,522,326 9/50 Winter 745 19 2,529,089 11/50 Leake 74-519 2,917,033 12/59 =Bmgren 123-90 5 CHARLES W. LANHAM, Primary Examiner.

BROUGHTON G. DURHAM, WILLIAM J.

STEPHENSON, Examiners. 

1. THAT PROCESS OF FORMING A ROCKER ARM COMPRISING SHAPING A PIECE OF SHEET METAL INTO A CHANNEL SHAPE HAVING OPPOSED SIDE WALLS EXTENDING UPWARDLY FROM THE BOTTOM OF THE CHANNEL SHAPE AND SO SHAPING THE SAME AS TO DEFORM THE BOTTOM OF THE CHANNEL DOWNWARDLY INTO A TROUGH EXTENDING TRANSVERSELY OF THE CHANNEL AND SPACED BETWEEN THE OPPOSITE ENDS THEREOF AND SO SHAPING SAID TROUGH THAT IT CONSTITUTES IN CROSS SECTION SUBSTANTIALLY A SEMI-CIRCLE, POSITIONING A SUPPORTING DIE HAVING AN UPWARDLY CONCAVE SUBSTANTIALLY SEMI-CIRCULAR IN CROSS SECTION BOTTOM END DIE FACE WHICH IS COMPLEMENTARY WITH THE SEMI-CIRCULAR CROSS SECTIONAL SHAPE OF SAID TROUGH BETWEEN THE SIDE WALLS OF THE CHANNEL SHAPE SUPERPOSING SAID TROUGH AND SUPPORTING SAID SIDE WALLS AGAINST PIERCING PRESSURE FROM THE OUTSIDE INWARDLY, AND SO POSITIONING SAID DIE THAT THE SEMI-CIRCULAR BOTTOM END FACE THEREOF FORMS SUBSTANTIALLY A CIRCULAR CONTINUATION OF THE INNER SEMI-CIRCULAR CONTOUR OF THE TROUGH, ADVANCING A PIERCING PUNCH WHICH CIRCULAR IN CROSS SECTION THROUGH EACH SIDE WALL OF THE CHANNEL SHAPE FROM THE OUTSIDE INWARDLY AND AT OPPOSITE ENDS OF THE TROUGH FORMING A CIRCULAR APERTURE IN EACH SIDE WALL OF THE CHANNEL SHAPE AND WHEREIN SAID TWO APERTURES ARE DISPOSED IN AXIAL ALIGNMENT AND WITH THE BOTTOM SUBSTANTIALLY SEMI-CIRCULAR PORTION OF EACH APERTURE REGISTERING WITH THE ARCUATE PLANAR CONTINUATION OF THE MAJOR PORTION OF THE SEMICIRCULAR CONTOUR OF THE SIDE WALL BOTTOM OF THE TROUGH AND WITH THE UPPER SEMI-CIRCULAR PORTION OF EACH APERTURE REGISTERING WITH THE CROSS SECTIONAL SHAPE OF THE BOTTOM END FACE OF THE SUPPORTING DIE THAT IS POSITIONED BETWEEN THE SIDE WALLS. 